1. Field of the Invention
This invention relates to a bladder carrying apparatus for carrying a bladder assembly held by a center mechanism of a tire vulcanizing press onto and off of the center mechanism in order to replace the bladder assembly.
2. Description of the Related Art
First, a tire vulcanizing press will be described with reference to FIG. 5. The tire vulcanizing press includes a lower metal mold secured to a lower mold mounting member 51, an upper metal mold 54 secured to an upper mold mounting member 53 for closing and opening movement toward and away from the lower metal mold 52, a pressurizing cylinder 56 for applying a pressurizing force to a pressurizing force transmitting rod 55 mounted uprightly on the upper mold mounting member 53, a center mechanism 57 disposed for upward and downward movement at a central portion of the lower mold mounting member 51, and a loader 60 including a chuck 59 having gripping members 58 disposed at circumferential positions spaced by an equal distance from each other thereon. Both of the lower metal mold 52 and the upper metal mold 54 has built-in heating means therein, and the center mechanism 57 includes an expansible bladder 61 for engaging an inner face of a green tire to effect shaping of the green tire while a heat medium is supplied thereto. The loader 60 is mounted for upward and downward movement and also for turning movement and can suspend a green tire thereon by gripping an upper bead ring portion of the green tire from the inner side by means of the gripping members 58 of the chuck 59. The loader 60 can thus load a green tire from a position outside the press to a predetermined position on the lower metal mold 52.
In the tire vulcanizing press described above, since the bladder 61 repeats an expanding and compressing deforming movement for each vulcanizing cycle in a high temperature, high pressure environment, it must necessarily be replaced with a new bladder after each 5 to 8 days, and also when such damage as a puncture or a perforation occurs or upon changing of the metal mold, replacement of the bladder 61 is required. Therefore, the bladder 61 is conventionally replaced as shown in FIG. 6, by using a carrying apparatus including a suspending equipment 65 such as a fork-lift, to replace a bladder assembly 68 which holds the upper and lower ends of the bladder 61 by means of an upper supporting member 66 and a lower supporting member 67, respectively. In this instance, a new bladder assembly 68 placed outside the press is suspended by the suspending equipment 65, moved to a location above the center of the tire vulcanizing press (much skill is required for centering in this instance) and then lowered. Then, the lower supporting member 67 is turned by hand or by some other means so that it may be screwed onto an upper portion 70a of a lift cylinder 70 of the center mechanism 57, and then, the upper supporting member 66 is secured to an upper end 71a of a piston rod 71 of the center mechanism 57 by means of a bracket 72 thereby mounting the new bladder assembly 68 onto the center mechanism 57. Removal of the old bladder assembly 68 is performed using a procedure reverse to that just described.
Using the conventional carrying apparatus including the suspending equipment 65 such as a fork-lift, however, since the bladder assembly 68 is positioned just above and then moved down to the center mechanism 57 while the fork-lift or a like apparatus is operated, there is the problem in that centering between them is difficult. Therefore, much time and labor are required for replacement of the bladder assembly 68, and also much skill is required.